Hunters have for years used tree mounted stands for certain types of hunting, such as deer and elk hunting. For example, U.S. Pat. No. 4,120,379 to Carter discloses a tree stand having a frame with two elongate frame members which lay directly against the side of a tree. A flexible cable extends around the tree and attaches at the top of the frame. A lower platform extends outwardly from the bottom of the frame providing a support upon which a hunter can stand. A seat extends outwardly from the frame near the top. The seat and platform are pivotally mounted to the frame allowing collapse of the frame for transport. The seat and platform are maintained in horizontal positions by suspension cables. Knife-like prongs are included at the bottom of the frame but not at the top. The Carter stand is disadvantaged by the direct bearing of the two longitudinal frame members upon the tree which substantially decreases stability of the frame due to irregularities in the tree surface. The Carter stand is further disadvantageous because the seat and platform cannot be folded up into a self-biasing retracted position after the stand has been hung in a tree. This causes snow and debris to build up when the stand is left in a tree.
U.S. Pat. No. 4,552,246 to Thomas discloses another foldable tree stand having a ring-like member which extends from the seat and encircles the tree trunk securing the stand thereto. A stanchion functioning as a ladder extends from the stand to the ground, providing additional support to the elevated stand. The Thomas stand is disadvantaged in that the seat and platform are not pivotal into retracted positions while the stand is mounted to a tree. The stanchion also limits the range of heights to which the unit can be employed.
U.S. Pat. No. 4,411,335 to Forrester discloses another tree stand having a horizontally oriented foot platform and seat. The tree stand is secured to a trunk by means of two chains which extend around the trunk and connect to upper and lower portions of the frame. Four spikes project from the frame and engage the tree. The tree is only engaged by horizontal members and the spikes thus causing instability. The platform and seat are not collapsible with respect to the frame.
U.S. Pat. No. 4,369,858 to Babb discloses a generally triangularly shaped tree stand having a horizontal foot platform and seat. An upper frame member extends angularly upward from the outer edge of the platform and is connected around the back side of the tree. A notched inner side of the platform frictionally engages the front side of the tree at a lower elevation and cooperates with the upper portion of the frame to support the stand on the tree. The seat and platform are not capable of being retracted while the stand is mounted to a tree, thus suffering the problems of snow and debris accumulations. The Babb stand also provides a very limited size of seat and platform and little vertical height for the seat thus placing strain on the user's knees.
U.S. Pat. No. 4,549,635 to Early discloses another tree stand, having a rigid U-shaped foot-resting frame and an upwardly extending seat support member pivotally connected thereto. A tree engaging support member angles upwardly from the U-shaped frame and is connected in a scissors arrangement with a seat support member. The two members are provided with special pieces for engaging the trunk of a tree at two vertically spaced points. The stand is secured to the tree by means of two ropes or cables which encircle the tree trunk at the upper and lower ends of the stand framework. The seat and platform are not retractable while the stand is mounted in a tree. The Early stand is also susceptible to lateral instability because of the two relatively narrow, vertically arranged points of contact.
Despite the numerous styles and constructions of tree stands shown in the art, none provide the high degree of stability needed for hunting and photography and desired by most other users. Stability is critical in such applications because even minute movements of the hunter or photographer in preparation of shooting will cause movement of the stand relative to the tree. Such movement of the stand will crunch the bark or otherwise cause noise alerting the prey or photographic subject to the hunter or photographer's presence thereby causing lost shots.
The prior art is further deficient in providing a tree stand which allows the platform and seat to be independently retracted while the stand is mounted in a tree. The prior art also does not show retractable platforms or seat constructions which are self-biasing into a nearly vertical over-center positions to prevent buildup of snow and debris during non-use but continued mounting in a tree.